The Shergotty meteorite is the first example of the shergottite Mars meteorite

Mars meteorite

A martian meteorite is a rock that formed on the planet Mars, was ejected from Mars by the impact of an asteroid or comet, and landed on the Earth. Of over 53000 meteorites that have been found on Earth, 99 are martian...

 family. It was a 5 kilograms (11 lb) Martian meteorite which fell to Earth at Shergotty (now Sherghati), in the Gaya district

Gaya District

Gaya is one of the thirty-eight districts of Bihar state, India. The district is having a common boundary with the Jharkhand state in the south. Gaya city is its largest city and the district headquarters.-History:...

, Bihar, India on 25 August 1865, and was retrieved by witnesses almost immediately. This meteorite is relatively young; radiometric dating

Radiometric dating

Radiometric dating is a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates...

 indicates that it solidified from a volcanic magma

Magma

Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...

 about 4.1 billion years ago. It is composed mostly of pyroxene

Pyroxene

The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. They share a common structure consisting of single chains of silica tetrahedra and they crystallize in the monoclinic and orthorhombic systems...

 and is thought to have undergone preterrestrial aqueous alteration for several centuries. Certain features within its interior are suggestive of being remnants of biofilm

Biofilm

A biofilm is an aggregate of microorganisms in which cells adhere to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance...

 and their associated microbial communities.